/*
 *
 * This file is part of QMapControl,
 * an open-source cross-platform map widget
 *
 * Copyright (C) 2007 - 2008 Kai Winter
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with QMapControl. If not, see <http://www.gnu.org/licenses/>.
 *
 * Contact e-mail: kaiwinter@gmx.de
 * Program URL   : http://qmapcontrol.sourceforge.net/
 *
 */

#ifndef IMAGEMANAGER_H
#define IMAGEMANAGER_H

#include "qmapcontrol_global.h"
#include <QObject>
#include <QPixmapCache>
#include <QDebug>
#include <QMutex>
#include <QFile>
#include <QDateTime>
#include <QBuffer>
#include <QDir>
#include <QNetworkDiskCache>

namespace qmapcontrol
{
class MapNetwork;
/**
@author Kai Winter <kaiwinter@gmx.de>
 */
class QMAPCONTROL_EXPORT ImageManager : public QObject
{
    Q_OBJECT

public:
    ImageManager(QObject *parent = 0);
    virtual ~ImageManager();

    //! returns a QPixmap of the asked image
    /*!
     * If this component doesn�t have the image a network query gets started to load it.
     * @param host the host of the image
     * @param path the path to the image
     * @return the pixmap of the asked image
     */
    QPixmap getImage(const QString &host, const QString &path);

    QPixmap prefetchImage(const QString &host, const QString &path);

    void receivedImage(const QPixmap pixmap, const QString &url);
    void fetchFailed(const QString &url);

    /*!
     * This method is called by MapNetwork, after all images in its queue were loaded.
     * The ImageManager emits a signal, which is used in MapControl to remove the zoom
     * image. The zoom image should be removed on Tile Images with transparency. Else the
     * zoom image stay visible behind the newly loaded tiles.
     */
    void loadingQueueEmpty();

    /*!
     * Aborts all current loading threads.
     * This is useful when changing the zoom-factor, though newly needed images loads
     * faster
     */
    void abortLoading();

    //! sets the proxy for HTTP connections
    /*!
     * This method sets the proxy for HTTP connections.
     * This is not provided by the current Qtopia version!
     * @param host the proxy�s hostname or ip
     * @param port the proxy�s port
     * @param username the proxy�s username
     * @param password the proxy�s password
     */
    void setProxy(QString host, int port, const QString username = QString(),
                  const QString password = QString());

    //! sets the cache directory for persistently saving map tiles
    /*!
     *
     * @param path the path where map tiles should be stored
     * @param qDiskSizeMB the about of disk space to use for caching. Default is 250MB
     */
    void setCacheDir(const QDir &path, const int qDiskSizeMB = 250);

    /*!
     * @return Number of images pending in the load queue
     */
    int loadQueueSize() const;

private:
    Q_DISABLE_COPY(ImageManager)

    QPixmap emptyPixmap;
    QPixmap loadingPixmap;

    MapNetwork *net;
    QNetworkDiskCache *diskCache;
    QVector<QString> prefetch;

    QHash<QString, QDateTime> failedFetches;

signals:
    void imageReceived();
    void loadingFinished();
};
}
#endif

